BACKGROUND: The objective of this study was to investigate the potential link between myopia in adolescents and exposure to per- and polyfluoroalkyl substances (PFASs). METHODS: This investigation included 1971 subjects with accessible PFAS level data, myopia status, and associated variables from four cycles of the National Health and Nutritional Examination Survey (NHANES). The investigation focused on specific PFAS compounds found in the serum, including perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS), chosen for their frequent detection. Owing to the skewed nature of the PFAS level data, the PFAS levels were log-transformed (Ln-PFAS) prior to analysis. Logistic regression, restricted cubic spline modeling, subgroup analysis, and sensitivity analysis were used to examine the associations between exposure to PFASs and the onset of myopia. RESULTS: PFOA levels were significantly associated with myopia risk (OR: 1.33; 95% CI: 1.05-1.69; P = 0.019). More specifically, with respect to the first quartile, the second quartile (OR_Q2: 1.69; 95% CI: 1.16-2.46; P = 0.007), third quartile (OR_Q3: 1.45; 95% CI: 1.03-2.03; P = 0.035), and highest quartile (OR_Q4: 1.58; 95% CI: 1.12-2.21; P = 0.010) of participants presented with increased myopia risk. Mediation analysis revealed that PFOA and myopia risk were partially mediated by serum albumin (ALB), with a mediation percentage of 22.48% (P = 0.008). A nonlinear inverted U-shaped relationship was identified between the level of PFOA and myopia risk (P for nonlinearity = 0.005). CONCLUSION Our findings suggest a potential link between exposure to PFOA and the likelihood of myopia development in young individuals and a mediating effect of serum ALB on this relationship. Notably, PFOA was identified as a key PFAS significantly contributing to the observed link between PFAS exposure and myopia risk. The potential threat of PFOA to myopia should be examined further.
Humans ; Fluorocarbons/adverse effects* ; Myopia/blood* ; Adolescent ; Male ; Female ; Prevalence ; Environmental Exposure/adverse effects* ; Nutrition Surveys ; Environmental Pollutants/adverse effects* ; United States/epidemiology* ; Alkanesulfonic Acids/blood* ; Caprylates/blood* ; Serum Albumin/metabolism* ; Child ; Sulfonic Acids

Abortion, Spontaneous/epidemiology* ; Adult ; Caprylates/blood* ; Case-Control Studies ; China ; Female ; Fluorocarbons/blood* ; Humans ; Pregnancy ; Pregnancy Trimester, First ; Prospective Studies ; Risk Factors ; Surveys and Questionnaires ; Young Adult

AIMTo study the protection of casein and protamine against degradation of insulin (INS) by proteolysis enzymes and the effect of these two kinds of protein on the hypoglycemic action of INS solution and enteric-microspheres after administrated orally to rats.

METHODSHPLC was used to determine the remained INS in the solution of alpha-chymotrypsin and trypsin with or without casein or protamine; INS solution and enteric-microspheres were prepared and adiministrated orally to rats together with the absorption enhancer sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC). At the same time, casein or protamine or both of these two kinds of protein were administrated together in order to study their influence on the hypoglycemic effect of INS and microspheres.

RESULTSCasein had a good protection against degradation of INS by alpha-chymotrypsin, but protamine had no protection effect. However, the degradation of INS by trypsin is concerned, the protection effect of protamine on INS was better that of casein. Both of protamine and casein can increase the hypoglycemic effect of INS solution and enteric-microspheres. Co-administrated these two kinds of protein had a better effect. In addition, co-administrated with SNAC, casein and protamine, INS enteric-microspheres had a longer and more potent hypoglycemic effect than that of the solution.

CONCLUSIONCasein and protamine can increase the stability of INS in the intestinal fluid by the mechanism of competition and combine with proteolysis enzymes, which will benefit to INS oral administration.

Administration, Oral ; Animals ; Blood Glucose ; metabolism ; Caprylates ; Caseins ; pharmacology ; Chymotrypsin ; antagonists & inhibitors ; Drug Delivery Systems ; Hypoglycemic Agents ; administration & dosage ; pharmacokinetics ; Insulin ; administration & dosage ; pharmacokinetics ; Male ; Microspheres ; Protamines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Solutions ; Trypsin ; pharmacology